Gear shift mechanism for transmissions



Sept. 11, 1956 J. A. ADLOFF GEAR SHIFT MECHANISM FOR TRANSMISSIONS 2 Sheets-Sheet 1 Filed Aug. 30, 1950 MW Attorneys Sept. 11, 1956 J. A. ADLOFF GEAR SHIFT MECHANISM FOR TRANSMISSIONS 2 Sheets-Sheet 2 Filed Aug. 30, 1950 my I a M, w r a B Q atent nice 2,762,235 Patented Sept. 11, 1956 GEAR SHIFT MECHANESM FOR TRANSMISSIONS Jakob August Adloff, Mainz-Gonsenheim, Germany, as-

signor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August '30, 1950, Serial No. 182,259

Claims priority, application Germany August 30, 1949 '12 Claims. (Cl. 74-477) This invention relates to an improvement of the gear shift mechanism for transmissions in which the shifting of gears is accomplished by axial displacement and rotation of a control rod placed parallel to the steering column. The control rod is actuated by a hand lever which is located preferably just under the steering wheel. The shift movement is transmitted to change gears in the transmission by links which transfer the motion of the control rod to the transmission housing and which shift the gears or synchronizing clutches. The advantage of this mechanism consists in the convenient accessibility of the shift lever and in the increase of leg room through elimination of the conventional lever. Gear shift mechanism of this type are known. It is one object of this invention to simplify the various component parts of the mechanism so that the complete mechanism is of lighter weight and can be more economically manufactured and assembled than the gear shift mechanism of this type known heretofore.

In this invention the control rod, actuated by the hand lever is slidably and rotatably mounted on guide pins, which are rigidly connected to the steering column and the steering gear housing respectively. The ends of the con trol rod are cranked, the upper end being forked and embracing a pin in the hand lever, while the lower end, bent like a finger, projects into a socket within a movably mounted sheath.

Attached to this sheath is the upper end of a connecting link transmitting the shifting movement to the transmission. Another sheath similar in construction to the aforementioned one is movably mounted on a ball stud, which is rigidly connected to the transmission housing. Into a socket of this latter sheath intrudes another ball stud, which cooperates with the axially and rotatably displaceable shift bar. The shift bar is borne in a boss of the side wall of the transmission housing and has a driving pin which engages either the shift segment controlling first and reverse gears or the shift segment controlling second and third gears. The shift segment which is not engaged by the shift bar is locked by a ball which is held in a cake located between the hub of the shift segment and the shift spindle, when the ball enters a radial bore within the hub of the shift segment, thus securing the shift segment against rotatable movement together with the shift bar. The lock ball of the shift segment which is engaged with the shift bar dodges in a ring groove of the shift bar.

Further details of the invention will be understood from the following specifications and the accompanying drawings illustrating an embodiment of the invention wherein:

Figure 1 is a plan view of the entire gear shift mechanism in which the upper part including the steering hand wheel is turned by 90 degrees.

Figure 2 is the lower end of the control rod partly shown in section.

Figure 3 shows a cross section along line 33 and Figure 4 is a cross section along line 44 of Figure 1 and Figure 5 is a side view of the transmission wherein the side wall is broken away.

In Figure l, the frame or chassis side rail of a motor vehicle is designated by 1 while 2 represents the engine, 3 the clutch housing and 4 the transmission assembly. The steering column 5 is attached at its lower end to the steering gear box 6 which is fixed to the chassis side rail 1.

In the steering column 5 the steering shaft is housed which connects the worm of the steering gear with the handwheel 7. Located parallel to the steering column 5 is the axially displaceable and rotatably mounted control rod 9. The upper end of the control rod 9 is journalled with its axial bore 10 on a guide pin 11 having an upset end 12 and is rigidly attached to the steering column 5, while the lower end of the control rod journals on a similar guide pin 14 having an upset head 15 and is fixed in the steering gear box 6. The guide pins 11 and 14 have intermediate their ends ball shaped enlargements 17, 18 respectively. The ball 17 of the upper guide pin 11 provides a fulcrum for the hand lever 8. The upper end of the control rod 9 is bent at right angle ending in a forked bearing 19 for the hearing pin 20 of hand lever 8 thus connecting control rod 9 and hand lever 8.

The lower end of control rod 9 (Figure 2) is cranked resembling a bent finger 21 which ends in a ball 22. The ball 22 and the ball 18 of guide pin 14 together with the sheath 23 form a joint transmitting the movements of the hand lever 8 to the connecting link 25, which is fixed to the sheath 23. When the control rod 9 is axially displaced in selecting a change speed group, ball 22 will travel on a straight line, while the sheath 23 performs a circular motion about ball 18 as a center, this will cause a slight variation in the distance of the centers of ball 18 and 22 which is compensated by spring 24. When selecting the desired speed gear hand lever 8 is performing a side to side motion causing a limited rotary or oscillatory motion of control rod 9. In this operation the lower end of control rod 9 and its cranked end portion, finger 21 and ball 22, will rotate or oscillate sheath 23 and connecting link 25 about ball 18 of guide pin 14 as a center.

Connecting link 25 transmits these movements to the shifting mechanism of the transmission. A bracket 26, in which a ball stud 27 is fixed, is rigidly attached to the transmission housing (Figure 3). Another ball stud 28 is connected to shift bar 30 by a link 29. The balls of the two studs 27 and 28 together with the transmission end of connecting link 25 and sheath 31 form a joint which is identical in construction to joint 18, 22, 24 at the steering column end. To compensate for variations in the distance between the balls 27 and 28 in selecting the speed group, spring 32 is interposed between the balls 27 and 28.

The shift bar 30 (Figure 4) rests within a sleeve 46 in the boss 33 of side wall 34 of the transmission housing and is rotatably or oscillatably and axially displaceable therein. 36 represents a dust cap which is provided between link 29 and an offset on shift bar 30. On the end which intrudes into the transmission housing shift bar 30 carries the shift levers 37 and 39 which operate the sliding gears by pawls 38 and 40. A dog pin 41 couples shift bar 30 with shift levers 37 or 39 respectively. To this end the shift levers are provided with slots 42 and 43 in a collar of their hubs which the dog pin engages. When dog pin 41 engages one of the shift levers, the other shift lever is locked. The locking device consists of balls 44 and 45 respectively which are held in a sleeve provided between shift bar 3 34) and each one of the shift levers. The shift bar 30 has also two ring grooves 67 and 48 which are spaced at a distance which is smaller than the distance of the ballsa44 and 45 w the travel or the shift bar when selecting the speed group. Inside the hubs of shift levers 37 and 39 there isa radial bore 49 and into vvliich either ball 44 or 45 will enter and lock the shift rlev'ei' against rotation. i H The individual gears are locked in a "cbh'venjtidnat manner by prin'g actuated balls 51(Eigd're 5) which engage notches of the shift levers 37 and 39, 1 y

In Figures 1 to 5 allthe val-ions shift el'eriients are shown in the position Whi ch they will have in selecting speedgronp for thi'rd ands'ecohd gear. This position will be automaticallyselected by the 'meen'anrsnr tinder the action of spring 52 located in bore of control rod m wh a gears ar'e 'nohmeshed. r V

i In case or reverse gear is abs selected, hand lever mnsLbe-rn'ov'ed towards hand 'vvheel 7 displacin qn rbfd rod 9 axially in Upward direction. Finger 21 tv ithball 22 at the lower end at control rod 9 --r .t?ttes, or os'eillat'es the sheath 24 and connecting iinktgs ab r t ban 1s. i i Transmitted to the transmission can o'fthe connecting link ;25 this movement canses a rotation or oscillation of sheath 31 lOlll.;-b3ll 27 Zli splacing ball 28 :a fid shift bar so ghan orig-41 enga es slot 43 or shift fever 3? and so-couple's shift lever 39 and shift bar 30. A't the same time ball 44 is lifted by sh 'o'jilder foil sliift bar lfitl andpnshed into bore 49 of maueversnaexnrg it againstrotation When haifd l'et7er'8 is new moved about guide 'pin'l lri. control rod 9 is rotated about its axis; sheath 2 andconne'cting link 25 perform a circulai' movement abont the axis of guide pin 14. Connecting link gs transmits t is movement to sheath'3'1 at t e transmission end of the connecting link and causesit 1g performjcirciilar movment about the axis er ball stud-2 7. Hereby shift barf 30 is rotated or oscillated and shift lever 39 actuated to select first or reverse-gear.

In a tran'smission control'mechanism a 'controd rdd sfi'p'por'tedfor rotary and reciprocating control movement on fixed "guide pins, a sheath cdhnering said "rod to one en'd'of a link, and asecond "sheath connecting the other; end of the link to a shift 'iaar'sap'parrea by the transmission housing forirotatabl e arid "axial control movement, to rotate said shift bar when saidcoritfoTl rod v is rotated, and to displaeesaid shift bar axial-1y when said fcontrol i tl isj r'eeip "atd. v e

-2. In-atransmissioin'eon ol irleehafilsifn emanation moun edjfor a xi al snare table d placement on fi'xe'd gnide pins, 913s [end or ttieJ'wdbemg bifitto "hgs e'a hand lever pivoted'oh ia ball farmed 'ono'ne offh'e ghi'de pins, 5;) ma erial pivotal '-'m sve1am of the handlever :the'- 'gi1ide pin reciprocates thiec'ifitroli'fid 'wlfile rotatable displaceh'ie'nfof -the hand lever rotates the 'control r'od. I 3. -In a transmission control rfieeh'anism a pfaiiof coirtrolledniemb'ers supported by a'sleevefsfip srfing a shift bar for rotatable and axial displacement, a'dog'pin fixed in said shift bar to sel ectively'engage on'ebfjth'e control member's tipo'naxialTdisplacerriefitfof the :shift b'ar, tvvo 'space d groove's in's aid shift b'ar't o receive "a locking ball ofthe geiecre iesfiso member, so that ipo'n engagement of-jonelcontrol memberby said dog'pingthefsfelected control; "errib'er and sh ift bar-"are 'eonnected'for rotatable displac rhentfwhi I the free cdntiol member is locked (against rotary displacenient with the sleeve stipportir'ig the 'shift'bar. V M H 4 n a transmission control iiiehhism a "c'd 'itrbl' ffit'l snpporte for rotary and reciprdcating contfol movement 'on fixed giiide pins, ,a sheath 'conneetin g rod fans-1a sitin hoii'siiigfbr rotatable and "aim displament; a pair of controlled members, and means forselecting and operating said controlled members, so that reciprocating of the control rod displaces the shift bar axially to select the controlled member, and rotation of the control rod rotates the shift bar to operate the selected controlled member.

tit-: 3 a t a sm s ion .t mro v. ms an s 2, p ort 1! L. 1. "a .M a. us. 1. a he t v.- .aJRt-Kaeoumember, a pair of controlled members rotatably mounted on said support member, a shift bar mounted on Sara sub-port mehiB-"er for axial and rotary cofitrol movement, means connecting said shift bar and "Sara seasoned ber t se e t 9f .s l qntw erl member in response to axial movement of said shift bar andto acih're "sict "seleted control member 'in' 'tespdnse to totary movement of said shift bar, and means responsive to said selective axial movement of said shift bar operably connected to the other of said controlled members to 9k sa o her .ccntr lcim mbsr. aga astrq et n-.. 1 ,Q- 111 at n m s QQ trQl msch it mtaiubn ar air.- i or a be a Pi LQfi ccnt dvma b r s ta a ly mo rned 9 .1 sai rfi u ar. PPQIl m mber. a sh P mounted sa dn ulzu ar s pi iqrt fiasmbtf fivisl and ta tr l niq ement and. .m m n ns h r. an aid. .9 1.tr 1.l memb t s sk e a said spnt c lls 'tasmb r n {wa e t l. Paveme said shift bar and to actuate said selected controlrnember in trespqnse to rotary movement of said shift bar.

Ina 1 transmission control mechanism, a tubj lr sup pzort, ,member, a pair L of controlled members r otatably nsu ated 91. si s ubu a UPPQ JP m q a h tk mo nte vw hins t d ub r. Support mbe -I ite and rotarycdntrol movement, means connecting said b r. id. a d..' t il d memb F$ j fi sa f said controlled membersin response to axial movement of said shift ba r and to actnateisaid selected control member in response to rotary movement f said shift barpand means-responsive to said selective axial rn s v'emea sit/ a rf thartp s x qotmcted t t e 6th?! Qfsaid controlled. members to lock said other controlled e b iist tatis gnide'pinsfix d oi s ds app rt a Q Ql 391 .32? a dsz sier-pin t.arlateta .proje i at we, a d 9 said comrql mdia an lev r pi tal xmou t 9 9 ofvsaidepins foraxialpivotal and. .frota y vp vota ,f 'p q movemencapivot l c nnec io b t e n saidrfiie; Z

and. -s id,ba d J v r o tr n ate a i l, vc alm i smc it dffsaid'hand leverjinto axial movement of said control rod and rotafy'pivotal movement of said hand lever into axial movement of said control rod.

10. In a transmission control mechanism, "a support, pinsjfixed'o'n said support, a control rod supported for reafymafi'pmasfig control movement "on'said pins, 2. laterally projecting arfri'hfitche'hd of said control tray lv "ivote'a "to she or s'aid 'pins'fbr'tixial igiv al n rotary vo ttil oversea d nt'iol lever isiifi'gdhneeted'toehe ofs'aidpfojec'ting' arnis to translate axialpivotal movement ofsaid control lever to axial" eveofsaid rBd and tiara" 'prvatar ind smear-1e aid ci'iiitreiit r'td rotary ari trehi' n tofsaidtodfabdnffolled lever pivotedon the other pmfor axial inveterate iaivcital' rhbvenieiit, an "said'controlled lever being connected t9 the other of said projecting said controlled lever and rotary movement of said rod to rotary pivotal movement of said controlled lever.

11. In a transmission control mechanism, a support, guide pins fixed on said support, a control rod supported for rotary and reciprocating control movement on said guide pins, a link, a first member pivoted to said support and connecting said rod to one end of said link, a transmission housing, a shift bar supported by said transmission housing for rotatable and axial control movement, and a second member pivoted to said transmission housing and connecting the other end of said link to said shift bar to rotate said shift bar when said control rod is rotated and to axially displace said shift bar when said control rod is reciprocated.

12. In a transmission control mechanism, a housing having a support portion, a pair of controlled members rotatably mounted on said support portion, an axially and rotatably displaceable shift bar supported by said support portion coaxially with said controlled members, and shift means operatively connecting said shaft bar and said controlled members to selectively engage one controlled member to said shift bar to actuate said one controlled member in response to rotatable movement of said shift bar, and locking means contacting said shift bar and said controlled members to lock the other controlled member to the housing in response to axial displacement of said shift bar.

References Cited in the file of this patent UNITED STATES PATENTS 2,170,794 Chayne Aug. 29, 1939 2,180,579 Butzbach Nov. 21, 1939 2,328,227 Orr Aug. 31, 1943 2,350,506 Haigh June 6, 1944 2,377,700 Kurtz June 5, 1945 2,497,930 Creson Feb. 21, 1950 

